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Hey guys was in the process of building a small block 357 and sold it to a guy and now I'm waiting on a 4.5 bore 10.2 deck brodix cast iron bbc block and a set of 340/119cc dragonslayer heads wondering what stroke ppl think I should think of I'm thinking 4.5 or 4.75 but not sure any advice would be much appreciated. Also any advice on a cam would be nice I'm gonna run 1.8 rockers with solid roller .700 max lift figured yall would need to know this stuff to know what to suggest thxs yall
 

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Depends on whether you need it to produce high RPM horsepower or need lots more bottom the mid torque. Generally less stroke is easier to get the engine to spin high RPM where the high horsepower is than to get a longer stroke motor to go there. Not that the latter can’t be done but because the longer stroke imparts higher velocities on the reciprocating parts it gets trickier to go there. Longer strokes provide bigger torque numbers per amount of displacement which by itself adds torque but the longer stroke at the level of conceptual basics it has more lever arm thus applies more force sooner. If you need lower RPM grunt this is the way to go. If you need high vehicle speeds the shorter stroke may prove the better route.

When you get into engines this big though it is easy to trim the performance with gearing whether that takes the form actual gears as in a wheeled vehicle or virtual gears as in prop pitch, diameter and blade count of a boat or aircraft.

So we’d need a better idea of what is your end use for this engine.

Bogie
 
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